Complete the indicated task to unlock the achievement.

Achievement	How to unlock
Aim bot (10)	Finish a level with accuracy >= 85%
Arachnophobia (10)	Kill the spider queen
Bugged (10)	Kill the bugs without using the flamethrower in the subway level
Chicken (10)	Beat the game on easy difficulty before beating it on normal or hard
Die already (10)	Kill the skull helicopter boss
Dopefish lives (10)	Find dopefish in the subway level
Eat that (10)	Kill 300 enemies with barrels, crates or rocks
Explorer (10)	Find the secret level
Fisticuffs (10)	Don't let core protector boss hit you with his melee attacks even once
Freedom (10)	Escape the prison
Fresh air (10)	Don't breath gas in the gas chamber trap
Gravity gun expert (10)	Deactivate all 3 scorpion spawners in the canyon
Hardcore (10)	Beat the game on hard difficulty
Heartbroken (10)	Finish a level without losing any lives (hearts)
I'm sorry, buddy (10)	Defeat the buddy boss
Impresses (10)	Kill 3 enemies with a single buzzsaw 2 times in a row
Kill the animals (10)	Destroy all the creatures in the jars in the laboratory level
Not a scratch (10)	Finish a level without taking any damage at all
Roasted (10)	Kill at least 50 enemies with flames
Save the animals (10)	Don't let creatures in the jars get destroyed in the laboratory level
That was close (10)	Finish a level with 0 lives left and health left < 25%
The end (10)	Kill professor Nathan and escape the facility
Turn back (10)	Get into dangerous places in the subway level
Worm feeling (10)	Don't let acid worms hit you while you're riding a boat